Measuring cuvette for spectrometric measuring instrument

ABSTRACT

A measuring vessel in which a gas to be analyzed by spectrometry is intended to flow, the vessel being in the form of a hollow tube provided with a reflective material forming an optical-reflection layer, including: a hollow tube is produced from a non-metallic material, and a removable supple optical article is applied against the internal surface of the hollow tube, the article including a supple flexible support, one face of the support being covered with a reflective metal material, the article being inserted in the tube so that the reflective metal material forms the optical-reflection layer.

TECHNICAL FIELD OF THE INVENTION

One subject matter of the invention is a measuring vessel for aspectrometry measurement apparatus. Another subject matter is aspectrometry measurement apparatus integrating such a vessel. Yetanother subject matter is a breathalyzer for measuring or detecting apartial gas level exhaled by a breath fluid and integrating thismeasuring vessel. Another subject matter thereof is a method formanufacturing a measuring vessel in which a gas to be analyzed byspectrometry is intended to flow. Finally, its subject matter is amethod for producing an electromagnetic barrier in a measuring vessel.

The invention relates to the technical field of elements constitutingspectrometry measurement apparatus, and more particularly elementsconstituting measuring vessels. It also concerns the technical field ofportable electronic devices, such as breathalyzers for example, formeasuring or detecting a partial gas level exhaled by a breath fluid.

PRIOR ART

A breathalyzer comprising a device emitting infrared radiation, aninfrared receiver and a measuring vessel in which the breath fluid forwhich a partial gas level is to be measured or detected flows is knownthrough the patent document FR 2.941.530 (SERFS ENVIRONNEMENT),hereinafter “SERFS document”. The measuring vessel is in the form of ametal hollow tube, the internal surface of which is provided with areflective material forming an optical-reflection layer.

In this type of apparatus, the metal tube fulfills a role ofelectromagnetic barrier that, in the measuring vessel, reduces anyexternal electromagnetic fields (electrical or radio-frequencyinterference, electromagnetic waves, etc.).

In practice, the metal tube of the SERFS document is relatively heavy.Furthermore, its internal surface requires a specific surface treatmentin order to form the optical-reflection layer. This treatment isgenerally complex to carry out and, in any event, is expensive.

A measuring vessel comprising a hollow tube similar to the tube of theSERFS document, and which has the same type of drawbacks, is also knownthrough the patent document EP 1.306.661 (AGILENT TECHNOLOGIES),

The invention aims to remedy this state of affairs. In particular, oneobjective of the invention is to propose an alternative solution forreducing the effects of electromagnetic fields external to the inside ofthe measuring vessel, this solution having to lead to a vessel which islighter, less expensive and easier to manufacture than the one describedin the SERFS document, while keeping the same optical quality.

Another objective of the invention is to propose a measuring vessel thatcan be adapted to any type of spectrometry measurement apparatus.

DISCLOSURE OF THE INVENTION

The solution proposed by the invention is a measuring vessel in which agas to be analyzed by spectrometry is intended to flow. It is in theform of a hollow tube provided with a reflective material forming anoptical-reflection layer. This vessel is remarkable in that:

-   -   the hollow tube is produced from a non-metallic material,    -   a removable supple optical article is applied against the        internal surface of the hollow tube, said article comprising a        supple flexible support, one face of said support being covered        with a reflective metal material, said article being inserted in        said tube so that said reflective metal material forms the        optical-reflection layer.

It is now the reflective metal material of the supple optical articlethat fulfills the role of electromagnetic barrier rather than the tube.The latter can therefore be produced from a non-metallic, lightweightand inexpensive material and its internal surface does not require anyparticular surface treatment unlike the one described in the SERFSdocument. Furthermore, the design of the measuring vessel is simplesince the optical article can be inserted in the hollow tube easily andquickly.

Other advantageous features of the measuring vessel that is the subjectmatter of the invention are listed below, each of these features beingable to be considered alone or in combination with the remarkablefeatures defined above:

-   -   The hollow tube preferentially has length of less than or equal        to 100 mm, the optical article having a length corresponding to        that of said tube.    -   The internal surface of the hollow tube advantageously comprises        elements in relief, the optical article being in contact with        the internal surfaces of said tube only at these elements in        relief.    -   The supple flexible support is advantageously produced from a        material chosen from the following group: polyimide,        polyepoxide, polyester, epoxy resin reinforced with glass fiber,        aluminum substrate.    -   The supple flexible support may have a thickness of between 1 μm        and 250 μm.    -   The reflective material forming the optical-reflection layer is        advantageously chosen from the following group: gold, cobalt,        silver, nickel, copper, aluminum, chromium, zinc.    -   A layer may be disposed between the reflective metal material        and the face of the supple flexible support, the material of        this layer being able to be chosen from the following group:        copper, aluminum, silver, polyethylene.

Another aspect of the invention relates to a spectrometry measurementapparatus comprising a measuring vessel in which a gas to be analyzed byspectrometry is intended to flow, the vessel being in the form of ahollow tube provided with a reflective material forming anoptical-reflection layer, said vessel being in accordance with the abovefeatures.

Yet another aspect of the invention relates to a breathalyzer formeasuring the partial gas level exhaled by a breath fluid, saidbreathalyzer comprising a device emitting infrared radiation, aninfrared receiver and a measuring vessel in which the breath fluidflows, the measuring vessel being in the form of a hollow tube providedwith a reflective material forming an optical-reflection layer. Thisbreathalyzer is remarkable in that:

-   -   the hollow tube is produced from a non-metallic material,    -   a removable supple optical article is applied against the        internal surface of the hollow tube, said article comprising a        supple flexible support, one face of said support being covered        with a reflective metal material, said article being positioned        in said tube so that said reflective metal material forms the        optical-reflection layer.

An additional aspect of the invention relates to a method formanufacturing a measuring vessel in which a gas to be analyzed byspectrometry is intended to flow, the vessel being in the form of ahollow tube provided with a reflective material forming anoptical-reflection layer. According to the invention, this methodconsists of:

-   -   i) producing the hollow tube from a non-metallic material,    -   ii) applying against the internal surface of the hollow tube: a        removable supple optical article, said article comprising a        supple flexible support, one face of said support being covered        with a reflective metal material, said article being positioned        in said tube so that said reflective metal material of said        article forms the optical-reflection layer. This step may        consist of: —rolling or bending the optical article; —then        inserting the optical article thus rolled or bent in the hollow        tube so that the reflective metal material of said article forms        the optical reflection layer.

A subsidiary aspect of the invention relates to a method for producingan electromagnetic barrier in a measuring vessel in which a gas to beanalyzed by spectrometry is intended to flow, the vessel being in theform of a hollow tube provided with a reflective material forming anoptical-reflection layer, said tube being produced from a non-metallicmaterial. The method consists of applying against the internal surfaceof the hollow tube: a removable supple optical article, said articlecomprising a supple flexible support, one face of said support beingcovered with a reflective metal material, said article being positionedin said tube so that the reflective metal material forms theoptical-reflection layer and forms an electromagnetic barrier betweenthe inside of the vessel and the internal surface of said tube.

DESCRIPTION OF THE FIGURES

Other advantages and features of the invention will emerge more clearlyfrom a reading of the description of a preferred embodiment thatfollows, with reference to the accompanying drawings, produced by way ofindicative and non-limitative examples, and in which:

FIG. 1 is a schematic view in cross section of an optical articleaccording to the invention,

FIG. 2 is a schematic plan view of an optical article according to FIG.1,

FIG. 3 is a schematic view in longitudinal section of a breathalyzeraccording to the invention,

FIG. 4 is a view in cross section along A-A of the breathalyzer of FIG.3.

PREFERRED EMBODIMENTS OF THE INVENTION

The measuring vessel that is the subject matter of the invention isparticularly, but not exclusively, intended to be used in a spectrometrymeasurement apparatus. It is in particular designed to be integrated ina breathalyzer, but may also be integrated in any other apparatus thatmeasures a parameter (concentration of alcohol, CO, CO₂, H₂0, etc.) in abreath fluid or in any other fluid (for example a vapor or an exhaustgas).

For reasons of clarity and concision, the remainder of the descriptionrefers only to a breathalyzer, without this being able to be consideredto be a limitation to the protection sought. “Breathalyzer” means,within the meaning of the present invention, any apparatus (includingethyl testing equipment) for measuring or detecting a partial gas levelexhaled by a breath fluid, and in particular measuring the concentrationof alcohol in the expired air and/or detecting an alcohol concentrationthreshold in the expired air.

FIG. 1 illustrates a supple optical article used to form the measuringvessel. This article 1 comprises a supple flexible support 10 consistingof a thin film having a thickness of between 1 μm and 250 μm,preferentially approximately 25 μm. A good suppleness/strength ratio isobtained with these thickness values. Its length and width are dependenton the dimensions of the measuring vessel in which it is integrated. Thesupport 10 is advantageously produced from a material chosen from thefollowing group: polyimide (e.g.: Kapton®), polyepoxide, polyester,epoxy resin reinforced with glass fiber, aluminum substrate (e.g.:COOL-CLAD® support marketed by the company Al TECHNOLOGY). Any othermaterial generally used for manufacturing supple printed circuits mayhowever be envisaged. The support 10 may be obtained by molding,extrusion, lamination, etc.

The support 10 comprises a top face 10 a and a bottom face 10 b that areopposite each other. In the accompanying FIG. 1, the top face 10 a iscovered with a reflective metal material 11 in order to form anoptical-reflection layer on which the infrared radiation will rebound.Provision can however be made for the reflective metal material 11 to bedeposited on the bottom face 10 b. So that the reflection layer is areflective as possible and so as to limit energy losses in the emittedradiation, the reflective metal material 11 is preferentially chosenfrom the following group: gold, cobalt, silver, nickel, copper,aluminum, chromium, zinc.

The reflective material 11 has a thickness of between 0.01 μm and 500μm. It may be deposited by adhesive bonding, electrochemical deposition,electrolytic deposition, printing, screen printing, vacuummetallization, heating, or by any other fine-layer adhesion method.

For the purpose of ensuring good holding in position of the reflectivematerial 11 on the top face 10 a of the support 10, an attachment layer12 may first be deposited on this face. This layer 12 consists forexample of a layer of copper, aluminum, silver or polyethylene, thethickness of which is for example between 0.1 μm and 500 μm, depositedby a fine-layer adhesion method of the type mentioned in the previousparagraph. The layer 12 is not essential and may in particular beavoided in the case where the reflective material 11 is for exampledeposited by electrolytic deposition.

The integration of the article 1 in the measuring vessel of a portablebreathalyzer will now be detailed with reference to FIGS. 3 and 4. Thisbreathalyzer E is of the type described in the aforementioned SERFSdocument. The measuring vessel is in the form of a hollow tube 20. Thelatter typically has a circular cross section but may have a square,rectangular, oval, etc. cross section. The tube 20 may be produced froma non-metallic material, for example plastics material (e.g. PVC, ABS),carbon composite material, etc. It may be obtained by molding, extrusionor any other method suitable for a person skilled in the art. Itsinternal surface does not require any particular surface treatment,unlike the one described in the SERFS document.

According to a preferred embodiment, the length of the tube 20 isbetween 5 mm and 200 mm, preferentially less than or equal to 100 mm,the invention making it possible to use a shorter measuring vessel thanthat of the SERFS document. Its inside diameter is less than 15 mm, forexample between 4 mm and 15 mm. And its thickness is less than 5 mm, forexample between 1 mm and 5 mm.

One end 20 a of the tube 20 is provided with a device 21 for emittinginfrared radiation, advantageously in wavelengths of between 1 μm and 12μm. The other end 20 b is provided with an infrared receiver 22. Theemitter 21 and the infrared receiver 22 are of the type known to personsskilled in the art. The breath fluid flows in the measuring vesselbetween the two ends 20 a, 20 b of the tube 20. More particularly, thefluid enters the tube 20 by means of an inlet nozzle 23 a (in which theuser blows) installed at the end 20 a, and emerges from said tube bymeans of an outlet nozzle 23 b installed at the opposite end 23 b Thetwo nozzles 23 a and 23 b may be situated on the same side of the tube20, or on the contrary on two opposite sides (FIG. 3). A pumping systemmay be associated with the nozzles 23 a and 23 b in order to ensure flowof the blown fluid sample.

The article 1 is inserted in the tube 20 so that the reflective metalmaterial 11 forms the optical-reflection layer. When the tube 20 has acircular cross section, the article 1 is rolled, manually orautomatically, so as to form a cylinder. In the case where the tube 20has not a circular cross section, but a square, rectangular or otherpolygonal-shaped cross section, the article 1 is bent so as to form atube having this particular cross section. The reflective metal material11 forms the internal surface of this cylinder (or tube). Thisarrangement optimizes the lengths of the optical paths in the tube 20,while keeping sufficient quantity of light as far as the receiver 22. Asa result the measuring vessel may be shorter than that of thebreathalyzer described in the SERFS document.

The optical article 1 has a length corresponding to that of the tube 20so that the internal surface of the latter is completely, orsubstantially completely, covered by said article. This is because somezones of the internal surface of the tube 20 may not be covered, inparticular at the ends 20 a and 20 b, while keeping an acceptablemeasuring quality.

The article 1 thus conformed is then inserted in the tube 20, at one ofthe ends 20 a or 20 b, so that the reflective material 11 forms theoptical-reflection layer against which the infrared radiation willrebound. In the configuration in FIG. 1, it is the internal face 10 b ofthe support 10 that is in contact with the internal surface of the tube20.

Thus positioned between the internal surface of the tube 20 and theinside of the measuring vessel, the optical article 1—and more preciselythe reflective metal material 11—forms an electromagnetic barrier. Allor parts of the external electromagnetic fields liable to enter insidethe measuring vessel and to interfere with the infrared receiver 20—andtherefore the precision of the measurement—are in fact stopped by thereflective metal material 11.

When the article 1 is formed, it has a natural tendency to unwind (orunfold) in order to regain its original flat shape. The result of thisability is that the article 1 is naturally held in position inside thetube 20 without its being necessary to provide another mechanical fixingsystem or one by adhesive bonding. Such a system may however beenvisaged as a precautionary measure.

The internal surface of the tube 20 may comprise elements in relief 200.The later consist for example of longitudinal or radial ribs, or in anyother form having hollows and protrusions on the internal surface of thetube 20. As is clear in FIG. 4, when the optical article 1 is insertedin the tube 20, it is in contact only with these elements in relief 200.

Once the article 1 is shaped and installed in the tube 20, and themeasuring vessel is thus manufactured, the other components 21, 22, 23a, 23 b are fitted.

With regard to the nozzles 23 a, 23 b, it is necessary that they emergeinside the measuring vessel, despite the presence of the article 1 thatcovers the internal surface of the tube 20. To do this, and as willappear in FIG. 2, the article 1 comprises notches, piercings or, moregenerally, recesses 100, the dimensions of which are adjusted to thediameters of the nozzles 23 a, 23 b. These recesses 100 are situated atthe lateral edges of the article 1. When the article 1 is shaped andinserted in the tube 10, the recesses 100 are placed opposite theemerging ends 230 a, 230 b of the nozzles 23 a, 23 b and leave thelatter free.

The arrangement of the various elements and/or means and/or steps of theinvention, in the embodiments described above, must not be understood asrequiring such an arrangement in all implementations. In any event, itwill be understood that various modifications may be made to theseelements and/or means and/or steps without departing from the spirit andscope of the invention. In particular, the measuring vessel may be usedfor processing signals other than infrared signals and/or with ananalysis technique other than spectrometry.

1-13. (canceled)
 14. A measuring vessel in which a gas to be analyzed byspectrometry is intended to flow, the vessel being in the form of ahollow tube provided with a reflective material forming anoptical-reflection layer, wherein the hollow tube is produced from anon-metallic material, a removable supple optical article is appliedagainst the internal surface of the hollow tube, said article comprisinga supple flexible support, one face of said support being covered with areflective metal material, said article being inserted in said tube sothat said reflective metal material forms the optical-reflection layer.15. The vessel according to claim 14, in which the hollow tube has alength less than or equal to 100 mm, the optical article having a lengthcorresponding to that of said tube.
 16. The vessel according to on claim14, in which the internal surface of the hollow tube comprises elementsin relief, the optical article being in contact with the internalsurface of said tube only at these elements in relief.
 17. The vesselaccording to claim 14, in which the supple flexible support is producedfrom a material chosen from the following group: polyimide, polyepoxide,polyester, epoxy resin reinforced with glass fiber, aluminum substrate.18. The vessel according to claim 14, in which the supple flexiblesupport has a thickness of between 1 μm and 250 μm.
 19. The vesselaccording to claim 14, in which the reflective metal material formingthe optical reflection layer is chosen from the following group: gold,cobalt, silver, nickel, copper, aluminum, chromium, zinc.
 20. The vesselaccording to claim 14, in which a layer is disposed between thereflective metal material and the face of the supple flexible support.21. The vessel according to claim 20, in which the material of the layeris chosen from the following group: copper, aluminum, silver,polyethylene
 22. A spectrometry measurement apparatus comprising ameasuring vessel in which a gas to be analyzed by spectrometry isintended to flow, the vessel being in the form of a hollow tube providedwith a reflective material forming an optical-reflection layer,characterized by the fact that said vessel is in accordance with claim14.
 23. A breathalyzer for measuring the partial gas level exhaled by abreath fluid, said breathalyzer comprising: a device emitting infraredradiation, an infrared receiver and a measuring vessel in which thebreath fluid flows, the measuring vessel being in the form of a hollowtube provided with a reflective material forming an optical-reflectionlayer, characterized by the fact that said vessel is in accordance withclaim 14: the hollow tube being produced from a non-metallic material, aremovable supple optical article being applied against the internalsurface of the hollow tube, said article comprising a supple flexiblesupport, one face of said support being covered with a reflectivemetallic material, said article being inserted in said tube so that saidreflective metallic material forms the optical-reflection layer.
 24. Amethod for manufacturing a measuring vessel in which a gas to beanalyzed by spectrometry is intended to flow, the vessel being in theform of a hollow tube provided with a reflective material forming anoptical-reflection layer, characterized by the fact that the methodcomprising: i) producing the hollow tube from a non-metallic material;and ii) applying against the internal surface of the hollow tube: aremovable supple optical article, said article comprising a suppleflexible support, one face of said support being covered with areflective metal material, said article being positioned in said tube sothat said reflective metal material of said article forms theoptical-reflection layer.
 25. The method according to claim 24, in whichfurther comprises: rolling or bending the optical article; and insertingthe optical article thus rolled or bent in the hollow tube so that thereflective metal material of said article forms the optical-reflectionlayer.
 26. A method for producing an electromagnetic barrier in ameasuring vessel in which a gas to be analyzed by spectrometry isintended to flow, the vessel being in the form of a hollow tube providedwith a reflective material forming an optical-reflection layer, saidtube being produced from a non-metallic material, the method comprising:applying against the internal surface of the hollow tube: a removablesupple optical article, said article comprising a supple flexiblesupport, one face of said support being covered with a reflective metalmaterial, said article being positioned in said tube so that thereflective metal material forms the optical-reflection layer and formsan electromagnetic barrier between the inside of the vessel and theinternal surface of said tube.